Closure



y 1960 M. L. GEISER ET AL 2,938,643

CLOSURE Filed Oct. 15, 1956 \4 /7' I INVENTOR 9 :j 11 6 a MILTON L.nausea v seems L. HERR United States Patent 1 2,938,643 CLOSURE MiltonL. Geiser, Manor Township, and George L. Herr,

West Lampeter Township, Lancaster County, Pa., assignors to ArmstrongCork Company, Lancaster, Pa., a corporation of Pennsylvania Filed Oct.15, 1956, Ser. No. 616,092 1 Claim. (Cl. 217-98) This invention relatesto a bung, and more particularly to an elastomeric bung to replace thecork bung for insertion in the bung bushing of a barrel.

The conventional tap bungs for barrels containing beer, ale, and thelike have been made from cork; however, due to recent economicconditions cork has become relatively expensive for this purpose, andalso with the development of certain synthetic plastic products suitablesubstitutes for cork have been developed for most uses.

In order for a bung to function properly for this purpose, it isnecessary that it be designed so that it can be driven easily into thebung bushing with existing driving equipment, will be held securely inposition in the bung bushing to prevent the pressure developed in thekeg from blowing the bung out of its sealing position, and also can bedriven on through the bung bushing into the keg when the tap pump isinserted to remove the beer from the keg. Due to the fact that it mustbe driven into the keg and also due to the fact that the interior of thebung is in engagement with the contents of the keg, it is essential thatthe bong be produced from materials which will not have a toxic or otherdeleterious effect on the contents of the keg.

Several attempts have been made to produce bungs from plastic materialsuch as polyethylene, and the general trend has been toward a bung whichforms a seal by providing a continuous ledge around the bottom edge ofthe bung which is exerted against the shoulder or bottom surface of thebung bushing. In order to insure'this seal, it is necessary to have arather heavily reinforced bottom edge on the skirt of the bung which isusually deformed during the insertion of the bung into the keg, whichdeformation impairs the sealing characteristics of the bung. When thisreinforcing ring is compressed during insertion, there is no spaceprovided into which the compressed material can be distributed. Becauseof this material distribution, the bottom skirt either develops a foldor the reinforced ring assumes an oval shape in the opening in the bungbushing. In the case of the fold, the material forming the bung isusually ruptured, resulting in an improper seal; and in the case of theassumed oval, the bung is cocked in the bushing to such an extent thatthe top edge of the opening in the bushing gouges sections from the sideof the hung. in either instance the sealing qualities of the bung aregreatly impaired.

Other plastic bungs have been developed having a scrim of ribs aroundthe skirt of the bung, giving line contact between the bung and thebushing at several points in the bushing. This line contact has not beensatisfactory due to the fact that bushings through reuse become scoredon their inner or sealing surface. With these score marks, it is noteasy to seal the contents of the barrel with a polyethylene bung havingseveral line contact points throughout the depth of the bung. Instructures having a plurality of sealing rings around the skirt of thebung, these rings are of necessity of such nature that they serve asreinforcing rings and prevent the expansion of the bung to permit thewall of the bung to be urged against the bushing by the internalpressure on the bung. Here again, with a plurality of reinforcing ringssurrounding the bung, there is no opportunity for the material in therings to be redistributed; therefore, the ring tries to assume an ovalshape and in so doing cocks the hung in the opening in the bushing,causing areas near the top'ofthebushing to be gouged.

Keeping in mind the limitations of the existingbung's, the hollow,cup-shaped bung of this invention was 'developed to be easily insertedwithout deformation 'of "the bottom of the cylindrical skirt and withoutcocking of the bung in the opening of thebun'g bushing, leaving arelatively large area of the skirt of the bung for sealing engagementwith the internal surface of the bushing, and at the same time providesuitably reinforced rings for sealing score marks in the bung bushing.

In order that our invention may be more readily understood, it will bedescribed in connection with the attached drawing, in which:

Figure l is an elevat-ional view of the bung;

Figure 2 is a cross sectional 'view of the bung taken on the line Illlof Figure 3;

Figure 3 is a plan view looking at the bottom of the bung;

Figure 4 is a sectional view of a bung bushing showing the position ofthe bung in sealing engagement therewith; and

Figure 5 is a view similar to Figure 4 showing a modified form of bungbushing.

Referring to Figure 1, there is shown a hung designated generally by thenumeral 2 having a relatively flat top portion 3 for engagement bydriving means to insert the bung in the bushing and to remove ittherefrom. The bung 2 has a relatively thin depending skirt .portion 4terminating in a beveled lip 5 having a diameter slightly less than thediameter of the bung opening in the bushing into which the bung is to bedriven. The bottom bfthe bung 2 is open for the admission of gaseouspressure into the bung cavity. Located adjacent the beveled portion ofthe bung are a plurality of locking lobes 6. These locking lobes 6 areso spaced around the periphery of the skirt as to leave areas 7positioned therebetween which are of relatively thin wall thickness. Thepurpose ofv the lobes 6 is to lock the bung firmly in engagement withthe bushing 3 (Figures 4 and 5) by means of the flat surface 9 on thetop of the lobe disposed angularly from the skirt of the bung, engagingthe underneath surface of the bushing. The top surfaces of all thelobes'6 are fiat and are disposed on substantially the same horizontalplane. The outer surface of the body of the lobes is tapered from theouter edge of the top surface 9 to the line where it blends into theskirt of the bung near its lower extremity. This tapered design in thearea 10 facilitates inserting the bung into the bushing -8. The lobes 6are also arcu'ate in a plane normal to the longitudinal axis of thebung, resulting in a lobe configuration in which the lobe graduallyblends into the surface of the skirt at all points except those lying onthe line where the top surface 9 joins the skirt of the bung. The lineat which the lobe blends into the skirt of the bung is designated by thenumeral 11. With this'design, when the bung is driven into'the bushing,the elastomeric material of which the lobe is comprised can beredistributed temporarily during the driving operation into the areabetween lobes so that the bottom skirt of the bung is not deformedduring the inserting operation. With the arcuate design as heredisclosed (Figure 3) there are no sharp angles presentto offerresistance to the redistribution of the elastomeric material during thisdriving operation. The resistance to redistribution caused by sharpangles results in pieces being broken oif the edges of the elastomericpiece. This tendency to break under compression is practicallyeliminated by this design. With a structure of this type, the bottomskirt of the bung has engaging means for engaging the bushing to lockthe hung in sealing position,- but at the same time there is nocontinuous reinforcing rib around the lower extremityof the bung toprevent the gaseous pressure exerted on the interior of the bung fromexpanding the bung into firm sealing engagement with the sides of thebushing. This is a highly desirable feature 7 because the lobes bythisspecific design'furnish two functionsone,. holding the bung in position;and second, l holding the bottom skirt of the hung in proper shape butjat the same time permitting therelatively thin side wall to expand dueto the internal pressure exerted, forcing the bung against the bushing'over a large area throughout substantially the entire depth'of the hungin the bushing. The seal effected between the smooth sides of the bungwith the bushing is satisfactory-withunmarred bushings; however,careless insert-ion of the tap rod in the bushing results in scoring theside of the bushing to, such an extent that the elastomeric material ofthe side wall of the bung will not distribute itself into the score"marks and the top portion ofthe bung but a heavily reinforced area 17 oneither side leading over toward the depending skirt. The purpose of thisreinforced area 17 is to impart to the bung sufiicientstrength'to'prevent thetap rod, which is used to push the bunglinto'tlie barrel, from puncturing thetop surface but instead the'lrod engagesthe hung in Y a relatively wide area over the heavily reinforced portionand pushes the entire bung into the barrel. This is a highly desirablefeature, inasmuch as the bung is completely removed from the bushingandcan be taken out of the barrel in one 'piece after the contents havebeen tapped therefrom. Another reason for this heavily reinforced area17 is that expressed earlier in connection with the sealing ring 13wherein the mass of material -17 acts I 'formity with' the formation ofthe opening in the bushing.

seal the score marks. In order to insure a proper seal in thoseinstances where score marks are present on the inner surface of thebushing, there are included on the bung here under consideration twosealing rings 12 and 13. The positioning'ofthese sealing rings'issuch'that a major portion of the smooth surface ofthe bung is exposedbetween the locking means 6 and the first sealing ring 12 to allowamplesealing surface for unmarred bushings. Also this ring 12 is sopositioned as not to 'restrict the expansion of the lower portion of theskirt of the bung.

" i The sealing ring 12 may be referred to as asemi-stifi fsealing ring.It is triangular in cross section, having a flat top surface and abeveled side extending from the outer'extremity of the flat ledge to theline where it blends into the body of the bung. In juxtaposition to thering 12 is a reinforcing ring 14 on the inner surface of the bung. Withthis'structure it will be obvious that the elastomeric material of thering 12 is forced into any score'lines'or other irregularities in thebushing by means '"of'theispring action of the barrel section of thebung further-supported by the inside reinforcing ring 14. As the'bung isdriven into the bushing, the ring 12 is squeezed j a I tween the bushingand the bung and assumes a flattened out configuration. f

The ring -12 does not cause cocking of the bung during the insertion ofthe bung into the bushing because the ring 12 itself does not havesuificient strength to resist deformation, and the reinforcing member 14which backs up'the ring 12 is of a diameter less than the diameter ofthe bushing and, therefore, does not offer the resistance.

a We have found polyethylene particularly well adapted for the purposeof carrying out this invention; however, any elastomeric materialcapable of deformation under the pressures used in inserting articles ofthis type is suitable, provided, of course, the material is so selectedas not to deleteriously aflfect the contents of the barrel.

It will be obvious to those skilled in the art that the plastic bungherein described is of such construction. that it may be easily driveninto a tap bushing without deforming the lower skirt of the bung,leaving a relatively large area of the skirt of the bung for sealingengagement with the tap bushing. The bung is also provided withauxiliary sealing means to seal against any deformities which may bepresent inthe interior surface of the bushing.

We claim: v 7

A cup-shaped bung for insertion into the bung bushing of a barrel, saidbung comprising a relatively heavy top said cylindrical skirt, thediameter of the terminal edge of the beveled portion being less than thediameter of the opening in the bushing, the flexible skirt of said bungbeing capable of expansion under. pressure to form a tight seal betweenthe bung and the bushing, a plurality of angularly projecting lobesdisposed on thebeveled'portion 'of the skirt to engage the under portionof the bushing the bushing, said lobesextending from the top of saidbeveled portion throughout substantially the entire depth thereof, theouter surface of said lobes tapering from the outer edges of said fiattop portions to the lower portions -material of the ring to conform tothe deformation and form a seal. The ring 13 is so positioned that whenit enters the opening in the bushing substantially the entire body ofthe bung is in the bushing and cocking of the bung is'thereby prevented.This resistance to cocking also aids in forcing the sealing ring 13 intoany deformitiesinthe bushing. V

From a study of Figure 5, it will be observed that sealing rings 12 and13 are so positioned that when used in bushings having the cork lockgroove 15 one of the sealing rings is located below the groove and theother is located above. It is, therefore, immediately apparent that allof 'the sealing features of this bung function on bushings having'thecork lock groove as well as on smooth bore bushings. i

The hollow cavity in the bung is arch-shaped as shown at 16, resultingin a relatively thin wall, in the center of or said lobes, said lobesbeing spaced from one another by segments of said beveled portion, anoutward circumferential projection in the sealing zone between the topsection and the flexible depending skirt, andan inner reinforcing ringin juxtaposition to said outward projection. a 7 I References Citedin'the file of this patent UNITED STATES PATENTS -mm- W he may

